Felt conditioner for paper-making machines



Sept. 19, 1939. Fjw WC ERY 2,173,317.

FELT CONDITIONER FOR PAPER-MAKING MACHINES Filed Feb. 27, 1937 v 4Sheets-Sheet l 1 l i r I I v &

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Sept. 19,1939. F. WQVI'cKERY 2, 7

FELT CONDITIONER FOR PAPER-MAKING MACHINES Filed Feb. 27, 1937 4Sheets-Sheet 2 73 36 //vv/vr0R ATTORNEY Sept. 19, 1939. v F. w. VICKERY2,173,317

FELT CONDITIONER FOR PAPER-MAKING MACHINES Filed Feb. 27, 1937 4Sheets-Sheet s Armswsr Sept. 19, 1939.

' FEM" CONDITIONER FOR PAPER-MAKING MACHINES Filed Feb. 27, 1937 4-Sheet 4 F. w. VICKERY 2,173,317"

Patented Sept. 19, 1939 UNITED STATES FELT CONDITIONER FOR PAPER-MAKINGMACHINES Frederick William Vickery, Westminster Bridge, London, EnglandApplication February 27, 1937, Serial No. 128,283

In Great Britain February 1, 1937 2 Claims.

This invention relates to the reconditioning of the felts ofpaper-making machines, by applying a reconditioning fluid, usuallywater, to the felt and immediately thereafter withdrawing it and thedirt dislodged by it by suction.

The object of the invention is an apparatus that will perform theseoperations with economy of power expenditure in the suction and pumpingplant, with a minimum of wear upon the felt,

and so as to leave the felt in substantially uniform conditionparticularly as regards moisture content.

To achieve this object the apparatus of the invention combines a suctionbox of less than the full working width of the felt maintained underhigh vacuum and separated from the felt by a'narrow perforated endlessband; a nozzle delivering fluid upon the surface of the felt in advanceof the point at which the suction box operates; guard means forconfining the fluid delivered by the jet to the width of felt upon whichthe suction b'ox is aboutv to operate; and means for traversing thesuction box, together with the nozzle and its guard means, to and froacross the felt.

The narrow suction box calls for only a small expenditure of power inthe suction plant to maintain a considerable degree of vacuum within it;and a considerable degree of vacuum is made possible without undue wearon the felt by the transference of wear mainly to the rubbing surfacesof the suction box and the interposed endless band; but because thesuction box is narrow the fluid delivered by the nozzle must be confinedv to less than the width of the suction box, for

if it substantially wets the felt beyond the width upon which thesuction box will straightway thereafter act, wet streaks may be left inthe felt which will impair the uniformity of the product,

While the fluid delivered by the jet may be sufficiently confined, formany purposes, by guard walls lightly contacting with the felt on eachside of it, it may be desirable, particularly where the jet is powerful,to support the felt against the thrust or lift of the jet, by holding itclown upon the jet by suction. To this end the invention contemplatesthe use of a suction box maintained at a relatively low suction,extending along opposite sides of the jet or surrounding it on threesides or wholly. This ensures penetration of the fluid into the felt andobviates any possibility of the felt being lifted so as to allow lateralescape of'the fluid.

The endless band may be a flexible band, which ll has the advantage thatit can be deformed to follow a substantially straight path where itcontacts with the felt and so prolong the time of action upon the felt.Or it may be a stiff ring to which external support can be given todiminish to any desired extent the pressure of 5 the ring upon thesuction box.

Other features of the invention will most conveniently be described withreference to the specific embodiments of the invention illustrated inthe accompanying drawings.

In these drawings,

Figures 1, 2 and 3 are respectively a longitudinal section, a plan (withthe ring in section) and an end elevation (omitting the ring)i. e. anelevation looking lengthwise of the felt-of a 5 construction with astiff ring;

Figures 4 and 5 show modifications that may be embodied in thisconstruction.

.Figures 6 and 7 are diagrammatic longitudinal and transverse sectionsof a construction with a 0 flexible band; e

Figures 8 and 9 show further details of the band.

Figures 10 and 11 are diagrammatic longitudinal section and planrespectively of a further 5 modification.

In the construction shown in Figures 1 to 3 the conditionercomprises acarriage I and a separate suction box casting 2 adjustably mounted onthe carriage by pin and slot connections 3. 30 The carriage rides uponan angle bar 4 which extends across the paper-making machine, and ismoved to andfro by mechanism now well known of which Figure lshows onlya half nut 5 adjustably supported from the carriage I be- 5 neath thebar 4. Connection is made at 6 to the interior of the suction box from asuitable suctlon pump.

' The surface of the suction box casting adjacent the felt 1 and aroundthe mouth 8 is 40 made cylindrical to fit a stiff perforated ring 9which contacts with the felt I and turns upon the suc tionmox casting.The ring may be of metal/but preferably it is built up of fabricimpregnated with synthetic resin. It is kept 5 concentric with thesurface of the suction box by guides l0 adjustably secured upon theedges of the carriage l. Laterally the ring is confined between flangesII on the suction box casting 2 V and by projections l2 on the guidesID, as ap- 5o pears more clearly from Figure 3 from which the ringitself has been omitted. If desired the lateral guides H and I2 maycontact with the ring 9 at a few points only, and the ring may be madewith Wavy edges (compare Figure 11), so

that as it turns it will be moved slightly from side to side upon thesuction box carrying with it the part of the felt with which it is incontact.

If a conditioning fluid is employed it may conveniently be injected bythe flat nozzle I3 into the angle between the ring 9 and the felt I; thenozzle I3 is carried upon a bracket I4 secured upon the suction box 2,and should be setat such an angle that at least a part of the fluidpenetrates the felt.

To confine the fluid laterally guard walls 34 are fitted on each side ofthe jet, lightly touching the felt. They may be joined by a bottom plate35 which will serve to carry off all fluid not temporarily retained inthe felt. In addition an interchangeable cross-bar 36 may be providedjoining the top edges of the guard walls 34, and adjustable to scrapethe surface of the felt. This will remove a great deal of the dirt andsome.

more of the cleaning fluid, all of which material will be led away bythe chute formed of the guide walls 34 and sloping bottom plate 35.

Wear between the ring 9 and the suction box casting may be reduced bysuitable lubrication. For instance renewable 'graphitic or otherantifriction blocks may be inset in the cylindrical surface of thecasting as diagrammatically indicated at 31. Or water may be injectedthrough a pipe l5 and channels such as l6 opening on the cylindricalsurface. Once the ring 9 has begun to turn the water supply to the pipel5 may be cut off, and water may be carried to the rubbing surfaces bymeans of buckets l1 formed in the inner surface of the ring 9 at itsedges, or felt pads l8 set in that surface. These may be filled orimpregnated by the water draining from the felt or by the cleaning jet43 directed upon the inner face of the ring 9. v

A further-alternative means of lessening friction between the ring 9 andthe suction box is to provide a yielding support to take the weight ofthe ring and the pressure of the felt upon it. For example as shown inFigure 4 a roller l9 bearing on the outer surface of the ringdiametrally opposite the suction box, may be carried upon a pivoted arm20 ,and resiliently pressed against the roll. Figure 4 shows the arm 28con nected to a piston 2| moving-in a cylinder 22 which communicateswith the suction box so that the greater the vacuum in the suction boxthe more strongly is the ring supported against the pressure of the feltwhich is drawn by the suction towards the suction box. By suitablechoice of the size of the piston 2| or by shifting its point ofconnection to the arm 20 the amount of lift given to the ring 9 can beadjusted to the best value for diminishing friction without occasioningleakage. The friction, upon a suction roll .extending the full width ofa felt may be reduced in similar fashion.

The suction box may be yieldingly supported so that it can adapt itselfto some extent to the ring in case the ring is displaced by the drag ofthe felt and maintain an even distribution of the pressure of the feltupon it. Figure 5, for example, shows the suction box formed at theoff-going side with a rounded end 23 which rests on a fixed support 24upon the carriage, while at the oncoming side the box rests on anadjustable abutment 25 and is guided bypins 26 entering slots 21.

Instead of being a. stiifring the perforated band interposed betweensuction box and feltmay be flexible. If desired the suction box maythen, as indicated in Figure 6, have a substantially flat top extendingparallel withthe felt to any desired length. Thus the time during whichthe felt is subject to suction need not be limited by the size of thering 9 and its arc of contact with the felt.. Figure 6 shows the band asconsisting of a flexible endless strip of non-rusting steel 28 to whichare riveted shallow open rubber boxes 29, having openings in theirbottoms registering with perforations in the band 28.

Where it passes over the flat surface of the suction box the band 28 isdeformed into a straight path by flanges 38 on the suction box, and dueto these and the suction the band is held tight upon renewablelubricating strips 3| set in the edges of the suction boxes.v In therest of its path the band may assume a substantially circular formwithout support, though a guide or guard 32 may be formed on the suctionbox casting within or beside the band. The rubber boxes 29 should bewedge-shaped so that their edges remain in contact even where the bandassumes a circular form, and their ends are preferably bowed out as seenat 33 in Figure 8 so that they will readily yield to allow the narrowingand lengthening of the boxes which occurs as they pass on to thestraight part of their path.

Alternatively the flexible band may be of rubber and canvas fabric,andbe fitted with transversely divided renewable ribs of hard rubber inlieu of the boxes 29. On the straight lengths of the band the blocks ofwhich the ribs are formed come into contact, or may tenonone into theother so as to make a substantially air-tight joint.

An alternative means of confining the conditioning fluid to the narrowstrip of the felt on which the travelling suction box is working isshown in Figures 10 and 11. Instead of the simple guard walls 34 asuction box 38 is provided extending along opposite sides of the jet l3or surrounding it on three sides or completely. But as only lightcontact is desired between this guard and the felt, the vacuum withinthe box 38 should be much less than that within the suction box 2. Tothis end a valve or other constriction 39 is placed in the branch pipe40 which connects the suction box 38 to the main suction pipe 4|; andbetween thisconstriction 39 and the suction box 38 there is provided aninwardly opening valve 42 which can be set to open at any desiredpressure difference.

I claim:

1. A felt conditioner comprising a support extending across the wholewidth of the felt parallel to the felt, a carriage thereon, means fortraversing said carriage along the support, a narrow suction box uponsaid carriage operating on a fraction of the working width of the felt,a perforated endless band passing between said suction box under areduced vacuum as compared with the principal suction box.

2. A felt conditioner comprising a support extending across the wholewidth of the felt parallel to the felt, a carriage thereon, means fortraversing said carriage along the support, a narrow suction box uponsaid carriage operating on a fraction of the working width of the felt,a. perforated endless band passing between said suction boxand the feltcontacting with the perimeter of the suction box and surrounding it andthe carriage, a nozzle upon said carriage directed into the anglebetween said endless band and the felt in advance of the suction box, anauxiliary suction box acting on the felt in rear of said nozzle and oneach side of said nozzle from a. point in ad vance of said nozzle to thearea acted on by the principal suction box, and means for maintainingsaid auxiliary suction box under a reduced vacuum as compared with theprincipal suction box.

FREDERICK WILLIAM VICKERY.

